Table 3 Summary of included studies 1991–2017

Hong [33]

2017

CO

Insurance claims 2010–2014

878,720 adults with acute uncompli-cated back pain and 492,805 adults with acute uncompli-cated headache

100,977 clinicians, including PCMD vs DC vs specialist MD

Imaging

1 year

DCs did less imaging (17%) than specialists (36.5%) and more than PCMD (13.3%). DCs had higher Odds Ratio (OR) higher for imaging if they

Owned X-ray equipment

Had imaged prior patient

Hurwitz [34]

2016

CO

Blue Cross Blue Shield of NC claims by NC State Health Plan for Teachers and State Employees 2000–2009

2,795,046 UNP claims and 529,318 complicated neck pain CNP claims 2000–2009

DC alone, MD + PT, MD + DC, referrals (hospitals, emergency medicine, specialists, etc.)

Total cost of care for ICD9 diagnosis for one fiscal year

1 fiscal year

Costs excluding referral services: For UNP or CNP, MD + PT > MD + DC

Costs including referral services: UNP or CNP: MD + PT > MD + DC

UNP total charges: 54%-84% lower for DC

Hurwitz [35]

2016

CO

Blue Cross Blue Shield of NC claims by NC State Health Plan for Teachers and State Employees 2000–2009

2,075,866 ULBP claims and 1,083,496 CLBP claims 2000–2009

DC alone, MD + DC, MD + DC, referrals (hospitals, EM,specialists, etc.)

Total cost of care for ICD9 diagnosis for one fiscal year

1 fiscal year

Costs for ULBP:

DC alone or MD + DC < MD alone or MD + PT

Costs for CLBP:

DC alone or MD + DC > MD alone or MD + PT

Risk-adjusted:

MD + DC < MD + PT and

MD alone > DC alone for ULBP and CLBP

Weeks [41]

2016

CO

Medicare data 2006–2012

40,720 multiply comorbid patients aged 66 and older with cLBP episodes who were enrolled in Medicare Part D (56.3% of the total sample of 72,326)

1) CMT alone; 2) CMT followed by MD; 3) MD followed by CMT; 4) MD alone

Cost of care including pain medications

per episode costs

Costs and episode length:

CMT alone < any other group

CMT + MD < ,MD alone

Weeks [40]

2016

CO

Medicare data

Medicare patients in 2011 within the 306 Dartmouth hospital referral regions

Areas with higher and lower DC use by Medicare patients

Opioid prescriptions and Medicare payments to DCs

1 year

Higher DC costs (more usage) were associated with lower opioid prescriptions, but not with lower opioid doses in those with prescriptions

Leininger [52]

2016

CS using RCT data

RCT data

241 adults aged ≥ 65

Home exercise and advice (HEA) vs spinal manipulative therapy (SMT) plus HEA vs SRE plus HEA

Direct and indirect healthcare costs and clinical outcomes (pain, disability and QALY)

1 year

On average, SMT + HEA had better clinical outcomes and lower total societal costs than SRE + HEA and HEA alone, with a 0.75 to 0.81 probability of cost-effectiveness for willingness to pay thresholds of $50,000 to $200,000 per QALY

Fritz [32]

2015

CO

Claims data from University of Utah Health Plans 2012–2013

747 patients with new LBP claim

First provider

Number of:

1 year

DC first:

1) Primary care MD 2) Physiatry

radiographs

Decreased risk for advanced imaging

3) DC

Advanced imaging

Surgeon visit

4) PT

Surgeon office visit

Increased episode of care duration

5) Spine surgeon-Ortho/ neuro

Surgical procedure

6) ER

Epidural injection

7) Specialist

LBP-related EM

Costs: total allowed costs for all claims

Keeney [26]

2013

PCO

Disability Risk Identification Study Cohort (D-RISC)

1885 WA state injured workers

First provider: DC vs. MD (occmed) vs MD (surgeon)

Early predictors of lumbar spine surgery, by type of provider

3 years

OR of surgery within 3 yrs: 1st provider-Surgeon 10.4; MD occmed 2.1; DC 0.2

Surgery:

43% of workers with surgeon first

2% with DC first

Graves [25]

2012

PCO

Disability Risk Identification Study Cohort (D-RISC)

1830 WA state injured workers

First provider: DC vs MD (primary care) vs MD (occ med) vs MD (surgeon) vs ED vs other type (specialist or physical med)

Early predictors of early MRI, by type of provider

3 years (2002–2004); early MRI = lumbar MRI ≤ 42 days post injury

IRR (incident rate ratio):

PCMD: 1.0

DC: 0.6

MD occ med: 1.4

Surgeon: 1.5

ED: 1.0

Other: 1.2

DC first:

approximately 50% lower likelihood of early MRI as compared to PC MD

Liliedah l[38]

2010

CO

Blue Cross/Blue Shield TN records 2004–2006

85,402 patients with LBP

First provider: DC vs MD/DO

Cost of LBP care per episode(Total episode costs included costs paid for all services provided during the episode by any providers, including pharmaceuticals

By episode during the 2-year study period

Cost of episodes with initial DC, adjusted for risk, were 20% less than with initial MD

Grieves [47]

2009

CS

WI private HMO insurance claims database of ~ 30,000

Patients with at least 1 medical or chiropractic visit for LBP

Primary medical vs chiropractic vs specialist medical care

Mean total back pain claims for procedures by provider (DC or MD); medication costs not included

2 years

Per case, mean chiropractic cost was $851 and for all forms of medical care, $2784

2004–2005

(n = 896)

Per case, median primary care medicine charges were $365; and $576 for all medical management; chiropractic $417 and specialist medical care $669

Haas [48]

2005

CS

Practice-based research network over 2-year period (1994–1996)

2872 patients with acute or chronic LB

Chiropractic care to primary medical care

Chart audit for a period of 12 months after baseline; office cost estimates based on Medicare/ ChiroCode relative value units and Medicare conversion factors. Estimated total costs included in-office costs plus estimated costs of advanced imaging, surgical consultation and physical therapist referrals

3 and 12 months from baseline visit

Adjusted DC office costs were 1.5–2.0 × greater than MD, but total costs of DC and MD treatment did not differ significantly at 3-months or 12-months when costs of advanced imaging and referrals are included

Greater improvement in pain and disability with DC care vs MD care, without additional costs

Kominski [50]

2005

CS using RCT data

RCT data from records of a large medical practice treating HMO patients

681 patients with LBP

MD only, MD + PT, DC only, DC + PM

Total outpatient costs, excluding pharmaceuticals

18 mo

Adjusted mean outpatient costs: MD + PT $760

DC + PM $579

DC $560

MD $369

Nelson [54]

2005

CS

Managed care insurance claims database from 1/1/97 through 3/30/01

Entire population of patients with chiropractic benefit (707,690) and without chiropractic benefit (1,001,995)

Insurance claims by patients for back or neck pain enrolled in medical plans with a chiropractic benefit vs those without a chiropractic benefit

Rates of advanced imaging, surgery, inpatient care, and plain-film radiographs

4-year

For patients with low back or neck pain use rates of all 4 studied procedures were significantly lower in the group with chiropractic coverage

Legorreta [51]

2004

CS

Administrative claims data from a large CA regional managed-care network

707,690 health plan members with an additional chiropractic coverage benefit; 1 M

Costs associated with episodes of care for patients with NMSK conditions receiving only DC care vs those receiving only MD care

Total healthcare claim costs, individual components of total costs (such as inpatient and outpatient services); costs of NMSK care at the episode level

4-year

Lower with DC care:

without the chiropractic benefit

12% per member per year (PMPY) excluding medication costs

13% PMPY costs with NMS patients

Mean cost of DC back pain treatment was $522 (8% lower than patients without chiropractic)

Complicated back pain episodes were only marginally higher (10% vs 8%) for MD vs DC care

DC back pain patients had significantly fewer hospital days; lower MRI rate; lower surgery rate, fewer radiographs, and were less likely to have comorbidities

Phelan [55]

2004

CS

1975–1994, North Carolina Industrial

43,650 claims

Total cost of medical vs chiropractic management of injured workers in NC

Lost work days, Temporary Total Disability (TTD), MD cost, DC cost, hospital inpatient cost, hospital outpatient cost, total medical cost, compensation paid, and total cost of claim

All closed claims 1975–1994

LB injury: mean costs were $3425 for MD and $634 for DC. Compensation payments averaged $15,819 for patients with MDs, $1912 with DCs

Commission closed injury claims

Mean lost workdays for MD care were 175; for DC care, 25. Mean total claim cost (including compensation) managed by MD was

$23,562; for DC it was $2597. Note: There was only 0.8% DC utilization in this study, compared to 85.4% MD utilization

Stano [61]

2002

CS

Practice-based research network (1994–1996)

2872 patients with acute or chronic LB

Total cost of care for 922 medical patients vs cost of care for 1,950 chiropractic patients

Office visits and treatment utilizing CPT, RVU

1 year from initial visit

Mean office cost of DC care $214; MD non-referral care $103 (including prescriptions); with same degree of relief. Referral treatment, surgery, post-surgical care and advanced imaging costs excluded

Cherkin [63]

1998

RCT

RCT data from Group Health Cooperative of Puget Sound HMO

321 adults with LBP that persisted for 7 days after primary care visit

PT McKenzie method vs CMT vs provision of an educational booklet

Total costs to the HMO (no out-of-pocket expenses) including medications

Treated for 1 month; followed up for 2 years

2-year mean costs:

PT $437

$429 CMT

$153 for the booklet group

No significant differences in clinical outcomes

Smith [57]

1997

CS

MEDSTAT data from approximately 2 million beneficiaries

1215 patients (medical or chiropractic first)

Total cost and outcomes of medical vs chiropractic care for NMSK diagnoses

Total costs via total insurance and outpatient payments and patient retention

2 years

Total insurance payments greater for medically initiated episodes. Patients who "cross over" between providers are more likely to return to chiropractic providers

Mosley [53]

1996

CS

HMO data 1994–1995

121 chiropractic patients and 1838 medical care patients

Chiropractic vs medical patients with neck or back pain

Total cost of care including diagnosis, imaging, prescription meds,

1 year

Overall costs per patient: chiropractic = $539 vs medical = $774

Imaging rate: chiropractic 5% vs 17% and cost/patient $31 vs $94

# of prescriptions/pt: chiropractic 1 vs 2, Rx avg cost: Chiropractic-$3.25, Medical = $7.20

Stano [62]

1996

CS

MEDSTAT data from approximately 2 million beneficiaries

6183 patients (medical or chiropractic first)

Chiropractic vs medical patients with NMSK diagnoses

Total costs and episodes

2 years

Mean total payments for first episodes: Chiropractic $518 vs $1020

Episode length: Chiropractic: 37 days vs 19 days

Shekelle [56]

1995

CS

RAND Health Insurance Experiment

686 patients

Chiropractic vs various types of medical care for patients with back pain (general practitioners, orthopedists, internist, DO, and all others.)

Number of visits per episode and mean costs per visit; total costs of episodes by provider type

4 wks before 1st visit to 4 wks after last visit

Mean provider cost/episode:

DC $264; Ortho $247; DO $238; PC MD $95. Mean costs per visit:

DC $19.45; PC MD $20.21; orthopedist $38.53, DO $22.18

Carey [23]

1995

PCO

Practice-based research network in NC

1633 patients with acute LBP

DC vs MD PC vs orthopedic surgeon

Total cost per episode of LBP (ambulatory)

24 weeks

Median costs/episode (urban):

DC $545

PCMD $169

Surgeon $383

Stano [60]

1994

CS

MEDSTAT claims data from 395,641 patients with neuromusculoskeletal conditions.1988–1990

Patients receiving only medical/DO care; only chiropractic care; or both

Chiropractic plus medical/DO care vs medical/DO care only for patients with NMSK diagnoses

Total costs and hospital admission rates

2 years

Overall lower costs for patients using both chiropractic and medical care are attributable to lower rate of hospital admissions. Total cost outcomes: DC only = $4379, MD only = $5360

Other spinal diagnoses also showed similar lower DC cost

Stano [59]

1993

CS

MEDSTAT data from approximately 2 million beneficiaries; 1988–1990

8928 patients with low back conditions with insurance that did not restrict chiropractic

Chiropractic vs medical/DO patients with LBP diagnoses

Total costs and episodes

2 years

Mean total payments:

Chiropractic $573 vs $1112

Episode length:

Chiropractic: 39 days vs 22 days

Stano [58]

1993

CS

MEDSTAT claims data from 395,641 patients with neuromusculoskeletal conditions

Patients receiving only medical care; only chiropractic care; or both

Chiropractic plus medical care vs medical care only for patients with NMSK diagnoses

Total costs and hospital admission rates

2 years

Lower costs for patients using both chiropractic and medical care are attributable to lower rate of hospital admissions

Jarvis [49]

1991

CS

Workers Compensation claims for UT 1986

3062 workers with back injury claims treated by either MD or DC

Chiropractic vs medical costs for workers with back injuries

Total cost per case of care and compensation

2 years

Mean cost of care: DC $527 vs MD $684

Mean days of compensation: DC 2 vs MD 21

Mean compensation:

DC $68 vs MD $668